Hose clamp and closing tool

ABSTRACT

A hose clamp for limited diameters, in the form of an open band ring having overlapping band ends, is manufactured from the band material of an insert as is used in conventional hose clamps for bridging an ear gap, such insert being typically made of steel according to DIN 1.4310 having a thickness of 0.3 mm. An opening is provided near one band end and a hook for engaging the opening is provided near the other band end. For closing this hose clamp, a gripper-type tool is used, the two jaws of which, in the closed condition, constitute an essentially uninterrupted inner surface having a diameter corresponding to the outer diameter of the closed hose clamp.

This application is the national stage of PCT Application PCT/EP02/02655filed Mar. 11, 2002, which claims benefit of EP Patent Application01106955.6 filed Mar. 20, 2001.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 4,312,101 discloses a hose clamp which, after having beenapplied to the hose/nipple connection to be sealed, is tightened bydeforming an ear provided in the clamp. To prevent the hose fromentering the ear during tightening and thereby being lifted off thenipple, the known hose clamp is provided with an insert made of bandmaterial which is inserted into the clamp so as to bridge the gap of theear.

While an easily deformable steel according to DIN 1.4301 having atypical thickness of 0.6 mm is used for normal hose clamps, specificallyclamps of the above-described type with an ear that is to be tightened,inserts are made of an essentially thinner material, typically steelaccording to DIN 1.4310 with a thickness of 0.2 to 0.4 mm which has highresiliency and high stiffness, is correspondingly difficult to deformand is therefore unsuited for ear clamps.

The present invention is based on the idea that a band material, whichis typical with such inserts for known hose clamps, is used formanufacturing the hose clamps themselves. In this way, the same startingmaterial is used for an additional purpose, resulting in a saving ofcost. In doing so, it is principally possible that finished inserts,which are intended for use with known hose clamps and are cut and formedto the shape provided therefor, are employed for making hose clampsaccording to the invention.

The embodiment wherein the material of the band ring is steel accordingto DIN 1.4310 having a thickness of 0.2 to 0.3 mm and wherein the bandring has border regions raised outwardly from a center portion thattakes a substantial part of the band width is advantageous for thestiffness of the hose clamp. Having the center portion of the band ringprovided with a curved cross-section or having the center portion of theband ring provided with an outwardly convexly curved cross-sectionprovides a hose clamp with an intrinsic prestress which is not onlyadvantageous for compensating tolerances but also ensures the hose clampto resiliently engage the hose when the hook in inserted in the opening.

Having the outer overlapping band end of the open band ring have itsterminal edge chamfered in the areas of raised border regions results inthe hose clamp being easy to close.

Having the hook partially punched and pressed out of the band materialwherein the hook in the closed condition projects beyond the planeportion of the band ring no further than the outwardly raised borderregions results in a hose clamp of low profile without any partsprojecting far radially outwardly.

A typical field of application of the hose clamp according to theinvention is where the hose clamps have a diameter of up to 20 mm,preferably 3 to 13 mm, wherein the band material has a width of 5 to 12mm, preferably 8 mm, and a thickness of at most 0.4 mm, preferably 0.3mm.

A tool for closing a hose clamp which consists of an open band ringhaving overlapping ends, an opening located in one band end and a hooklocated in the other band end for engaging the opening, specifically forclosing the hose clamp wherein the tool is formed as a pair gripperswith two jaws which in the closed condition form an inner surface havinga diameter corresponding to the outer diameter of the closed hose clampand wherein the inner surfaces of the jaws form a smooth cylindricalsurface over their substantial width with enlarged border regions isparticularly suited for closing the hose clamp according to theinvention. This tool permits performing the closure by means of a simplegripper movement with the hook engaging # the opening.

Having the jaws of the tool form a substantially uninterrupted innersurface in the closed condition and having the jaws be exchangeable inaccordance with the diameter of the respective hose clamp are suitablemeasures to ensure a uniform closure of the hose clamp to a cylindricalring.

Having the tips of the jaws overlap each other in the closed conditionand having the tips of the jaws have their widths reduced tosubstantially one-half, ensures that the hose clamp is engaged by thetool over its entire circumference.

Wherein, in the hinge region, one gripper arm is formed by two legs,with the other gripper arm crossing between the two legs or wherein thetip of one jaw has two outer tines between which a central tine formedat the tip of the other jaw engages in the closed condition of thegrippers, are of advantage in that they safely prevent canting duringclosure, which could result in deviations of the finished, closed hoseclamp from the cylindrical shape.

A preferred embodiment of the invention will now be explained in moredetail with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a hose clamp in the open condition,

FIG. 2 shows the same hose clamp in the closed condition,

FIGS. 3 a to 3 c represent cross-sections through the hose clamp,

FIG. 4 illustrates an open tool with an open hose clamp inserted,

FIG. 5 shows the same tool in the closed condition, and

FIG. 6 shows a modified jaw structure for the tool.

DETAILED DESCRIPTION OF THE DRAWINGS

According to FIG. 1, the hose clamp consists of an open band ring 10 ofsteel according to DIN 1.4310, which is pre-bent such that the band ends11, 12 overlap each other. A rectangular opening 13 is punched from theouter overlapping band end 11 while a hook 14 is formed in the innerband end 12 by partial punching and pressing out of the band material.The closed condition of the hose clamp represented in FIG. 2 is ensuredby the hook 14 engaging the opening 13.

The thickness of the band material is at most 0.4 mm, preferably 0.3 mm;its width is typically between 5 and 12 mm, and is preferably 8 mm. Sucha band material is suitable specifically for hose clamps which, in theclosed condition shown in FIG. 2, have an inner diameter of up to 20 mm,preferably between 3 and 13 mm. The maximum diameter may be over 20 mmif suitable closing means (grippers) are available.

As shown in FIGS. 1 and 2, the band ring 10 has a center portion 15which takes the substantial width of the ring, and outwardly raisedborder regions 16. With a total width of the band ring 10 of 8 mm, thewidth of each raised border region 16 is approximately 1 mm.

The amount by which the outer edges 17 of the band ring 10 projectbeyond its centre portion 15 corresponds at least to the thickness ofthe band material.

The hook 14 has its open end bent out of the band ring 10 by an amountwhich is somewhat larger than the thickness of the band material. Thisensures a safe anchoring of the hook 14 at the corresponding edge of theopening 13 in the closed condition of the hose clamp.

The outwardly raised border regions 16 serve not only to increase thestiffness of the band ring 10; their effect is also that the hook 14 inthe engaged condition does not project beyond the outer profile of theband ring 10, thereby reducing the chance of the hook 14 to becomeinadvertently disengaged from the opening 13, resulting in the hoseclamp to open. Further, the outwardly raised border regions 16 serve forthe mutual guidance of the two and ends until the hook 14 snaps into theopening 13. Finally, the raised border regions 16 are also of advantagein that sharp edges are avoided which could cut into the hose to besealed.

The outer overlapping band end 11 is chamfered at both sides, as shownat 18 in FIGS. 1 and 2, in such a way that the terminal edge 19 has alength which substantially corresponds to the width of the centreportion 15 of the band ring 10. The chamfers 18 serve for betterguidance and centring during bending and closing of the hose clamp.

The band ring 10 shown in FIGS. 1 and 2 has the cross-sectionrepresented in FIG. 3 a in which the centre portion 15 is cylindrical.Alternatively, as shown in FIGS. 3 b and 3 c, the region 15′, 15″ may beprovided with an outwardly convex or concave curvature to give the bandring 10 an elasticity reserve. As a result of this, the hose clamp iseasier to close and, after hooking, resiliently engages the hose to besealed. At the same time, the clamp is less critical to tolerances.

The tool 20 represented in FIGS. 4 and 5 for closing the hose clampshown in FIGS. 1 and 2 is in the form of grippers, the jaws 21, 22 ofwhich, in the closed condition represented in FIG. 5, constitute apractically uninterrupted cylindrical inner surface with a diametercorresponding to the outer diameter of the closed clamp 10.

In cross-section, this inner surface is shaped complementarily to theouter surface of the clamp 10; in other words, the inner surfaces of thejaws 21, 22 have a cylindrical center portion with enlarged borderregions. This complementary shape not only ensures that the hose clamp10 is completely closed; it also causes the hose clamp 10 to be centredand aligned during closing.

The tips 23, 24 of the jaws 21, 22 are reduced to half the width oftheir main portions so that they overlap each other in their closedcondition. This avoids an interruption of the cylindrical surface of thejaws 21, 22 surrounding the hose clamp in the closed condition of thetool 20.

The gripper arm 25 carrying the jaw 21 is formed with two legs in theregion of the pivot pin 26, and the gripper arm 27 carrying the jaw 22crosses the arm 25 between the two legs thereof. This avoids cantingwith the result that the jaws 21, 22 close precisely to the saidcylindrical shape.

In a modification shown in FIG. 6 of the drawings, the tips of the jawsmay be shaped such that one 29 of them has a central tine 30 which inthe closed condition engages between two outer tines 28 provided on theother jaw 31. This structure also avoids canting.

In order to close hose clamps of different diameters using the samegrippers, the jaws may be exchangeable, with a corresponding pair ofjaws being used for each hose clamp. As an alternative, the jaws may beprovided with prismatic inner surfaces.

The embodiment described above with reference to FIGS. 4 and 5 relatesto a special tool designed specifically for closing the hose clamp ofFIGS. 1 to 3. For the same purpose, commonly available pipe wrencheswith adaptable diameters may be used, such as grippers common in theelectrical field which have exchangeable half-shell shaped jaws that canbe selected in accordance with the diameter of the hose clamp.

1. A hose clamp made of an open band ring (10) and having overlappingband ends (11, 12), an opening (13) disposed in one band end (11), and ahook (14) disposed in the other band end (12) for engaging the opening(13), characterised in that the band ring (10) is made of the materialof a hose clamp insert having a thickness of up to 0.4 mm.
 2. The hoseclamp of claim 1 wherein the material of the band ring (10) is steelaccording to DIN 1.4310 having a thickness of 0.2 to 0.3 mm.
 3. The hoseclamp of claim 1 wherein the band ring (10) has border regions (16)raised outwardly from a centre portion (15) that takes a substantialpart of the band width.
 4. The hose clamp of claim 3 wherein the centreportion (15) of the band ring (10) has a curved cross-section.
 5. Thehose clamp of claim 4 wherein the centre portion (15) of the band ring(10) has an outwardly convexly curved cross-section.
 6. The hose clampof any one of claims 3 to 5 wherein the outer overlapping band end (11)has its terminal edge (19) chamfered in the areas of the raised borderregions (16).
 7. The hose clamp of any preceding claim wherein the hook(14) is partially punched and pressed out of the band material.
 8. Thehose clamp of claim 7 wherein the hook (14) in the closed conditionprojects beyond the plane portion of the band ring (10) no further thanthe outwardly raised border regions (16).
 9. The hose clamp of anypreceding claim, having a diameter of up to 20 mm, preferably 3 to 13mm, wherein the band material has a width of 5 to 12 mm, preferably 8mm, and a thickness of at most 0.4 mm, preferably 0.3 mm.
 10. A tool forclosing a hose clamp which consists of an open band ring (10) havingoverlapping ends, an opening (13) located in one band end (11) and ahook (14) located in the other band end (12) for engaging the opening(13), specifically for closing the hose clamp of any preceding claim,characterised in that the tool (20) is formed as a pair grippers the twojaws (21, 22) of which in the closed condition form an inner surfacehaving a diameter corresponding to the outer diameter of the closed hoseclamp, wherein the inner surfaces of the jaws (21, 22) form a smoothcylindrical surface over their substantial width with enlarged borderregions.
 11. The tool of claim 10 wherein the jaws (21, 22) in theclosed condition form a substantially uninterrupted inner surface. 12.The tool of claim 10 or claim 11 wherein the jaws are exchangeable inaccordance with the diameter of the respective hose clamp.
 13. The toolof any one of claims 10 to 12 wherein the tips (23, 24) of the jaws (21,22) overlap each other in the closed condition.
 14. The tool of claim 13wherein the tips (23, 24) of the jaws (21, 22) have their widths reducedto substantially one-half.
 15. The tool of any one of claims 10 to 13wherein, in the hinge region (26), one gripper arm (25) is formed by twolegs, with the other gripper arm (27) crossing between the two legs. 16.The tool of claim 15 wherein the tip of one jaw has two outer tinesbetween which a central tine formed at the tip of the other jaw engagesin the closed condition of the grippers.